Impact wrench



April 2, 1963 J. E. KINNISON 3,083,598

IMPACT WRENCH Filed Jan. 7. 1960 4 INVENTOR 2 Jay/v '5 MAW/5'0 AGENTnited States This invention relates to an impact wrench.

Impact wrenches are generally used for tightening or loosening largenuts on bolts which connect parts of heavy machinery or structures.These large nuts require a substantial amount of force properly totighten or loosen them. Such large nuts cannot be properly tightened bya conventional torque tool pulled by manual force and therefore animpact tool is used for such purposes.

The usual impact tool, commonly known as a slug wrench, is generallystruck by a hammer to tighten or loosen large screw threaded nuts. Thesetools are readily usable when there is sufficient room to swing a heavyhammer, however, in restricted areas slug wrenches are difl'icult touse, time consuming, and oftentimes dangerous. Furthermore, conventionalslug wrenches have striking faces which may not be effectively utilizedif surroundings of the wrench limit application of striking force from aposition disposed angularly to the arm of the wrench. In such instances,a hammer tends to glance off the striking face of a slug wrench and maystrike the operator or adjacent objects and thereby create considerabledamage. In many positions of slug wrenches within machine structures itis impossible to strike a slug wrench normal to its striking surfacewhich renders the slug wrench very diificult to operate.

Accordingly, it is an object of the invention to provide an impact orslug wrench having a nut engaging portion and an extending arm havingstriking faces with recesses internally of the planes of the strikingfaces wherein a punch or bar may be used to impart an impact force tothe arm of the wrench to thereby tighten a nut; said recess permittingan impact member to be nested therein and to be disposed at variousangles relative to the axes of the arm of the wrench so that force maybe applied eiiectively to the arm from such angularly disposedpositions.

Another object of the invention is to provide an impact tool having anut engaging portion and an arm which may be engaged by an impact toolfrom various angles and which also has striking faces which may bestruck by a conventional hammer without injuring recesses in the armwhich receive the angularly disposed impact tools.

Another object of the invention is to provide an impact tool of thisclass which may be utilized in restricted areas where it is necessary toapply fprce to the arm of the wrench at various angles to the axisthereof,

Another object of the invention is to provide an impact tool which isvery eflicient in the tightening of large nuts and which is safe to theoperator thereof.

Another object of the invention is to provide an impact tool which mayreadily be engaged by a hydraulic jack in order to apply torque to thewrench or impact tool.

Another object 9f the invention is to provide an impro e en e c n n a lr c t pe imp c tools,

Another object of the invention is to provide an impact tool which maybe engaged and forced from various ane by a g at rie y f i pac or p weoo equ pment.

Another object of the invention is to provide an impact tool having anut engaging portion and an arm extending therefromi said arm havingrecesses therein, the geometry of which readily retains the end of apower tool punch therein when disposed at various angles to the axis ofthe arm of the tool, whereby great force may be applied to if we thetool by a punch in one of the recesses without said punch sliding fromthe recess in the arm.

Other objects and advantages of the invention may be apparent from thefollowing specification, appended claims and accompanying drawings inwhich:

FIG. 1 is a side elevational view of an impact tool of the slug wrenchtype showing improvements according to the present invention.

FIG. 2 is a plan sectional view taken from the line 2-2 of FIG. 1showing the application of various power or impact tools at variousangles to the arm of the present impact tool of the invention.

FIG. 3 is a diagrammatic view of a hydraulic power jack in position tocooperate with the impact tool of the present invention.

FIG. 4 is an enlarged fragmentary sectional view taken on substantiallythe same plane as FIG. 2; and

FIG. 5 is an enlarged transverse sectional view taken from the line 55of FIG. 4.

The impact tool or slug wrench of the present invention is provided withan arm or body 10 having an integral head or Work engaging end 12internally of which there are nut engaging portions 14. It will beunderstood that this head 12 may have a variety of structures forengaging a nut and may be of various dimensions as desired.

Integral with the arm 10 is a power receiving end 16 of the wrench. Thispower receiving end 16 is provided with slug impact faces 18 and 20which are opposed to each other and parallel with the axis of the nutengaging portions 14. These faces 18 and 20 may be struck by aconventional hammer if desired. Recesses 22 and 24 inwardly of thesefaces 18 and 20, respectively, are provided to receive bars or punchesof various impact tools as will be hereinafter described in detail. Therecesses 22 and 24 shown in FIG. 2 are shown on enlarged scale in FIG. 4of the drawings. 7

With reference to FIG. 4 of the drawings, it will be seen that theserecesses 22 and 24 are identical and therefore the geometry of therecess 22 will be hereinafter described. This recess is elongatedlongitudinally of the arm 10 and is provided with short radius portions26 and 28 in its opposite ends adapted to receive ends of P nches or aor t e pp on of force to the 10 when applied at various angles to the ofthe arm.

s sh wn in F 2 of he dra ings, fo xampl a. punch A may be struck from aremote position by a ham! mer B and this punch A may be at such an anglethat it will engage the short radius portion 26 as shown in FIG. 4 ofthe drawings; it being assumed that the strug, ture surrounding thewrench or impact tool will impose the angular position of the punch Aand the remote posi? tion of the hammer B. This arrangement permitsimpact force to be applied to the arm 10 of the wrench by the hammer Band from an acute angle to the axis of the arm 10. Likewise, an handimpact tool C may be used to apply force to a punch D. Also, a strikingbar B may be operated manually and this bar may be a long heavy ba h chy en e cen ly of o a n e d of one of the recesses 22 or 24,

Further references to FIG, 2 of the drawings will in: e that n i p ct to P w ich may b d i en e1ee= lly or p um c ly ay pply o ce by m ans ofits P n h 6 t o t ra i s'p rti n 26 of eith r of the recesses 22 or 24.The acute angular relationship of the punch G relative to the arm 10 maybe dictated by cramped or restricted space occasioned by surroundingstructure at the location in which the wrench or impact tool isoperated,

With reference to FIG. 3 of the drawings, it will be seen that the arm10 is engaged at the recess 24 by a plunger 30 of a hydraulic jack 32 orother suitable pressure tool supported on a plane H of a stationarystructure. Coupled to this jack 32 by means of a flexible hydraulic tnhe3,4 is a manual pump 35; having -a manual pliinger lever 38'proyidedwith aleverage factor to develop high hydraulic pressureswithin the tube '34 and jack 52 ,or ,other means-of controlled pressureforce.

Coupled to'the tubefig is a gauge 40 which may be calibrated in footpounds of torque according to the radius of the arm 11) of the impacttool at a point engaged by the plunger 30 and also in accordance withthe proper tions of the hydraulic system. Thus, the jack 32 may beproportionedfor a' torque wrench in accordance with the presentinvention having a given length of the arm 10. V V.

. It will be understood that the hydraulic jack 32 may apply tremendousforce to the arm of the impact tool shown in FIG. 3 of the drawings andmay be used from varions angular positions as desired and in accordancereadily ltiflg'age these recesses. ,Normally, it is possible a "to resetthe wrench for each angular increment of the n t htenin ca r n n t e fopa m y be applied until the wrenchhas moyed a few degrees Wherenpign itmay he reseton the nut as desired. In the case of a square nut, theresetting of the wrench may require rotation of ninety degrees for eachincrement of tightening anidiit' contemplated that the recesses 22 and"Ma er eta Pun es pp y force thro gh ut a retational anglenf ninetydegrees with respect to the nut engaging portions of the head 12. Thus,the arm 10 ma'yirotate ninety degrees and still retain a punch in eitherof the recesses 22 and 24 regardlessqf the angle at which the punchesor-tools are applied to the recesses. Reference isagain made to FIG. 4of the drawings wherei th S ort adiu Po t ons 26 nd 8 e n a p nch ethough it is 'dispnsed at, an acute angle to the arm '10.

Itwill he ob :ous to those skilledin the art that various modificationsof the present invention may be resorted to in a manner limited only bya just interpretation of mana g c ims:

- 4 I claim: 1. In an impact wrench the combination of a wrench armhaving a head provided with a nut engaging portion; said arm also havingan impact or power receiving end provided with opposed striking facesthereon; said 7 arm being provided with recess portions inwardly of saidopposed striking faces and communicating with the outer planes of saidfaces; said recess portions being disposed to receive impact tools atvarious angles to the axis of said arm. I

2. In an'impact wrench the combination of: a wrench arm having a headprovided with a nut engaging portion; said arm also having an impact orpower receiving end provided wtih opposed striking faces thereon; saidarm being provided with recess portions inwardly of said opposedstriking faces and communicating with the outer planes of said faces;said recess portions being disposed to receive impact tools at variousangles to the axis of said arm, said recesses being elongatedlongitudinally of said arm and having short "radius portions at oppositeends there t Sa d e s mean b i elon a d ngi n ly or said arm and havingshortradius portions at opposite ends thereof d' posed tosupport the endof a punch angularly disposed to the axis of the arm.

References Gited in the file of this patent UNIT-ED s'rA r s PATENTS 7an impact tool of the class described the com "b l g l Qfan a m; a u n ne d 'ed b a power receiving end'of said arm opposite from said head'andhaving recess means therein disposed to re- "ceive a punch for theapplication of force to said arm, 'said recess means heing sufficientlydeep to permit said punch to apply force to said arm at an angle to theaxis

1. IN AN IMPACT WRENCH THE COMBINATION OF A WRENCH ARM HAVING A HEADPROVIDED WITH A NUT ENGAGING PORTION; SAID ARM ALSO HAVING AN IMPACT ORPOWER RECEIVING END PROVIDED WITH OPPOSED STRIKING FACES THEREON; SAIDARM BEING PROVIDED WITH RECESS PORTIONS INWARDLY OF SAID OPPOSEDSTRIKING FACES AND COMMUNICATING WITH THE OUTER PLANES OF SAID FACES;SAID RECESS PORTIONS BEING DISPOSED TO RECEIVE IMPACT TOOLS AT VARIOUSANGLES TO THE AXIS OF SAID ARM.